Name of Presentation: Can Arrival Processes be Modelled by Simple Waves?

Abstract: Like many customer arrival processes, patient arrivals to the psychiatric ward or the emergency department (ED) exhibit strong cyclic behaviour. In this talk we investigate whether arrival rates can be approximated by a simple sum of sinusoids. Such models can potentially bridge the gap between analytic modelling and high resolution simulations: They are simple enough to be tractable for the former, but may also be accurate enough to use for the latter for prescriptive capacity planning.

We discuss some unexpected estimation pitfalls that can arise when estimating the frequency components in the arrival rate using intuitive heuristics. Motivated by these concerns, we propose a simple graphical solution that has surprisingly good performance guarantees. To aid capacity planning, we apply the procedure to patient arrivals data from the Yale ED.